Prosthetic teeth and mold making therefor

ABSTRACT

A prosthetic tooth having an enamel layer which has a zone of substantially constant thickness. This tooth is molded using a dental tooth mold part prepared by imaging a dental pattern of a prosthetic tooth shade layer and/or shader mold part outer surface, and forming the dental pattern in a mold by program directed milling. A family of prosthetic teeth is provided including a first tooth in a first set of teeth having a first overall labial length, and a first back length, and a second tooth in a second set of teeth having a second overall labial length, and a second back length. The invention provides a prosthetic incisor tooth including a tooth body having two generally symmetrical curved grooves between three curved ridges on the labial face of the body at the incisal end of the body. The grooves are deepest at the incisal end and extend substantially from the incisal edge to at least about 15 percent of the overall tooth length.

This application is a division of application Ser. No. 08/528,832, filedSep. 15, 1995, now U.S. Pat. No. 5,718,585.

The invention relates to prosthetic teeth and the fabrication of moldparts to make prosthetic teeth. The invention provides multiple partdental tooth molds and prosthetic teeth with an enamel layer havingzones of uniform thickness. Prosthetic teeth in accordance with apreferred embodiment of the invention are readily articulable withinsets and proportionally consistent within families. Prosthetic teeth inaccordance with the invention are useful for making full and/or partialdentures, and as crowns, implant teeth and shade guides havingprosthetic teeth thereon.

Tooth molds are used in the dental industry for the manufacture ofartificial teeth. Refining steps include a final finish-polish step,which provides a mold of high-definition of the surface properties ofthe artificial tooth to be produced by molding tooth making materialtherein.

Dehoff et al in U.S. Pat. No. 5,452,219 (Case 1619) disclose a methodfor making a tooth mold. Erdle in Australia 124,083 disclose ceramicarticles and material and method for coloring or shading the same.Saffir in U.S. Pat. No. 2,380,568 disclose artificial tooth. Kelly inU.S. Pat. No. 2,514,075 disclose artificial tooth. Erdle in U.S. Pat.No. 2,517,100 disclose method of forming ceramic articles and producingdifferent colors or shades along different potions of the article.Budish in U.S. Pat. No. 2,643,455 disclose artificial teeth. Rydin inU.S. Pat. No. 2,677,150 disclose method in producing artificial teeth.Slack, Jr. in U.S. Pat. No. 2,678,470 disclose polymerizing method.Saffir in U.S. Pat. No. 3,126,429 disclose method of casting teethhaving different colored layers. Connan in U.S. Pat. No. 3,218,711disclose artificial teeth. Swinson in U.S. Pat. No. 3,861,044 teaches amethod of fitting a tooth with a dental inlay. Heitlinger et al. in U.S.Pat. No. 4,324,546 disclose an apparatus and method for the manufactureof dentures. Tanaka in U.S. Pat. No. 4,392,829 disclose metal porcelaindental restoration and method of making. Faunce in U.S. Pat. No.4,433,959 disclose composite laminate dental veneer containing colorsystems. White in U.S. Pat. No. 4,436,684 describes methods of makingthree dimension models and mold cavities of internal body structure.

Tanaka in U.S. Pat. No. 4,481,227 disclose method of coloring bakableporcelain dental restorations. Moermann et al. in U.S. Pat. No.4,575,805 disclose a method and a apparatus for the fabrication ofcustom-shaped implants.

Duret et al. in U.S. Pat. No. 4,611,288 describe a system for taking animpression of a body region for the production of a prosthesis.

Moermann et al. in U.S. Pat. No. 4,615,678 teach a blank from which animplant can be machined by an apparatus of the type disclosed in U.S.Pat. No. 4,575,805. Miller in U.S. Pat. No. 4,617,159 disclose method ofmolding a dental shade sample. Amdur et al. in U.S. Pat. No. 4,645,454disclose porcelain products and methods. Blair et al. in U.S. Pat. No.4,650,418 disclose dental restoration shading. Duret et al. in U.S. Pat.Nos. 4,663,720 and 4,742,464 disclose a method of making a dentalprosthesis. Watanabe et al. in U.S. Pat. No. 4,681,633 disclose highstrength calcium phosphate glass ceramic materials. Corbett in U.S. Pat.No. 4,722,689 disclose coated temporary dental crowns. Brandestini etal. in U.S. Pat. No. 4,766,704 describe a method and apparatus formachining a custom-shaped dental restorative part from a blank of dentalmaterial in a single operation. Brandestini et al. in U.S. Pat. No.4,837,732 teach a method of facilitating acquisition of data definingthe three-dimensional shape of prepared teeth and their immediatevicinity.

Rotsaert in U.S. Pat. No. 4,970,032 disclose processes for themanufacture of artificial teeth and crowns. Grossman et al. in U.S. Pat.No. 5,089,306 disclose glazing dental constructs. Hasegawa et al. inU.S. Pat. No. 5,127,834 disclose artificial teeth and method for makingthem. Rotsaert in U.S. Pat. No. 5,151,044 disclose blanks for themanufacture of artificial teeth and crowns. Emmons in U.S. Pat. No.5,308,243 disclose method and compositions for producing life-likedental porcelain restorations and dental porcelain restorations soproduced. Oden in U.S. Pat. No. 5,342,201 disclose method ofmanufacturing ceramic artificial tooth restorations.

It is an object of the invention to provide artificial teeth with anenamel layer having zones of constant thickness.

It is an object of the invention to provide a family of prostheticteeth, including a first tooth in a first set of teeth having a firstoverall labial length, and a first back length, and a second tooth in asecond set of teeth having a second overall labial length, and a secondback length, wherein the ratio of the first to the second overall labiallength is substantially equal to the ratio of the first to the secondback length.

It is an object of the invention to provide a prosthetic tooth includinga tooth body having two generally symmetrical curved grooves betweenthree curved ridges on the labial face of the body at the incisal end ofthe body, wherein the grooves are deepest at the incisal end and extendsubstantially from the incisal edge to at least about 15 percent of theoverall tooth length.

It is an object of the invention to provide an image of at least aportion of at least one upper tooth and at least one lower tooth, eachsaid tooth being from the same side of the same set of teeth, modifyinginitial data corresponding to the image to form modified data, moldingmodified prosthetic teeth in molds made using the modified data,whereby, during articulation the modified prosthetic teeth contact alonga larger proportion of tooth surface than prosthetic teeth made in moldsusing the initial data.

Set of teeth as used herein refers to teeth to be used for the sameindividual, such as is a single denture whether full or partial.

Family of teeth as used herein refers to sets of teeth of differentsizes and/or shades but having common shapes.

SUMMARY OF THE INVENTION

A prosthetic tooth having an enamel layer which has a zone ofsubstantially constant thickness. This tooth is molded using a dentaltooth mold part prepared by imaging a dental pattern of a prosthetictooth shade layer and/or shader mold part outer surface, and forming thedental pattern in a mold by program directed milling.

The invention provides a family of prosthetic teeth, including a firsttooth in a first set of teeth has a first overall labial length, and afirst back length, and a second tooth in a second set of teeth has asecond overall labial length, and a second back length. The ratio of thefirst overall labial length to the second overall labial length issubstantially equal to the ratio of the first back length to the secondback length. Preferably the first tooth has a first shade length and thesecond tooth has a second shade length and the ratio of the first shadelength to the first overall labial length is substantially equal to theratio of the second shade length to the second overall labial length.

The invention provides a prosthetic tooth including a tooth body havingtwo generally symmetrical curved grooves between three curved ridges onthe labial face of the body at the incisal end of the body. The groovesare deepest at the incisal end and extend substantially from the incisaledge to at least about 15 percent of the overall tooth length.

The invention provides a method of making readily articulable prostheticteeth by displaying an image of at least a portion of at least one uppertooth and at least one lower tooth from the same side of the same set ofteeth, then modifying initial data corresponding to the image to formmodified data, molding readily articulable prosthetic teeth in moldsmade using the modified data, whereby, during articulation the readilyarticulable prosthetic teeth contact along a larger proportion of toothsurface than prosthetic teeth made in molds using the initial data.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic side view of a prosthetic tooth in accordance withthe invention.

FIG. 1A is a partial schematic side view of a prosthetic tooth inaccordance with the invention.

FIG. 2 is a schematic perspective view of a system displaying an enamellayer and an enamel mold part in accordance with the present invention.

FIG. 3 is a schematic perspective view of a system displaying a shadelayer and a shader mold part in accordance with the invention.

FIG. 4 is a schematic perspective view of a system displaying a secondback layer and a second back mold part in accordance with the invention.

FIG. 5 is a schematic perspective view of a of a system displaying aback layer and a back mold part in accordance with the invention.

FIG. 5A is a schematic perspective view of a system displaying upper andlower molar teeth in accordance with the invention.

FIG. 6 is a schematic view of a family of prosthetic tooth sets inaccordance with the invention.

FIG. 7 is a schematic view of a shade guide member in accordance withthe invention.

FIG. 8 is a schematic side cross sectional view of an implant crown inaccordance with the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The invention is now described with more particular references to FIGS.1-8. A prosthetic tooth 100 in accordance with a preferred embodiment ofthe invention includes enamel layer 102 having labial face 104 andshader face 106, shade layer 108 having enamel face 110 and back face112 and back layer 114 having shader face 116 as shown in FIG. 1. Theoverall tooth length (TL) as used herein refers to the distance measuredalong the elongated central axis (E) of the tooth from the tip of theincisal edge (I) of a tooth to the point (BE) on the edge of back 114furthest from the incisal edge (I).

Overall labial length (L) as used herein refers to the distance measuredalong the elongated central axis (E) of the tooth from the tip of theincisal edge (I) of a tooth to the point (PL) on the outer face of theneck of the tooth midway between the highest and the lowest points onthe neck as shown in FIG. 1.

Back length (B) as used herein refers to the distance measured along theelongated central axis (E) of the tooth from the tip of the incisal edge(I) of a tooth to the end of the second back layer (PB) which ispreferably about the highest point on the neck as shown in FIG. 1. Theshade layer thickness (ST) at the midpoint (PMB) of the back length (B)is preferably about 0.09 inch.

Shade layer length (S) as used herein refers to the distance measuredalong the elongated central axis (E) of the tooth from the tip of theincisal edge (I) of a tooth to the point (PS) wherein the enamel layerchanges from decreasing to constant thickness as shown in FIG. 1. Theenamel thickness (ET) at the midpoint (PMS) of the shade layer length(s)is preferably about 0.031 inch.

Multiple layered teeth are provided that have a uniform thickness ofenamel across a latitudinal cross section from the neck of the tooth tothe center of the labial surface. This uniform enamel thickness isimaged by offsetting a copy of the labial surface of an anterior toothand partially shaping the offset copy of the enamel surface into acurved surface to form an image of a shade layer outer surface. A shadermold part is later cut into a solid block of material, preferably metal,to provide a mold surface corresponding to the image of the shade layerouter surface.

As shown in FIGS. 1 and 1A prosthetic tooth 100 includes an enamel layer102 having a zone Z of substantially constant enamel thickness. Theenamel thickness extending normal to the central axis E of the tooth atany point, for example point 150, selected on the labial face 104 iswithin 0.003 inch of the thickness at any other point within 0.005 inchof the selected point. In a preferred embodiment of the invention theenamel thickness has an average thickness and said average thicknessvaries less than 20 percent within said zone, and said zone is circularhaving a diameter of at least 0.01 inch. The zone of substantiallyconstant thickness extends preferably at least between 20 percent and 75percent of the overall labial length of the tooth. Preferably thesubstantially constant enamel thickness varies less than 25 percentwithin any enamel zone which extends normal to the shade layer, and thezone is at least 2 mm² more preferably at least 4 mm² and mostpreferably at least 8 mm². More preferably the substantially constantenamel thickness varies less than 20 percent within the zone. Preferablythe area of the zone is substantially circular. Preferably the enamelthickness is between about 0.003 and about 0.03 inches. Preferably theenamel thickness is between about 0.08 and 0.03 inches toward theincisal end of the tooth. Preferably the enamel thickness is less than0.003 inches toward the back end of the tooth. Preferably the tooth hasa neck member. Preferably the tooth includes two overall symmetricalregions between three substantially thicker regions on the labial faceof the body at the incisal end of the body between 0 and 20 percent ofthe overall tooth length.

Preferably within a family of teeth multi-layered anterior teeth areprovided that have constant dimensional ratios. These dimensions aremeasured on longitudinal cross sections of the teeth from the family ofteeth as shown in FIGS. 1 and 6.

Posterior teeth are provided in accordance with the invention that haveconstant dimensional ratios. All teeth within a family of such teethexhibit similar characteristics for making a denture. Articulation ofupper and lower teeth made in accordance with the invention is easierand more complete than it is for prior art teeth. Small, medium andlarge teeth within a family all exhibit the same articulationcharacteristics.

Three-dimensional tooth surface, tooth layer, and/or tooth mold partpatterns are displayed on video display monitors from stored, editedand/or digitized data. The operator examines, measures and/or modifiesqualities of the surface pattern such as the size and shape of the toothand labial striations, desired for the dental mold. By visual analysisand comparison to known geometric values, e.g., length, width,thickness, for the teeth, the operator determines to add, and/or omitdata via input devices, such as a keyboard. A desired three-dimensionalsurface pattern is thus created and displayed.

The data used for the three-dimensional surface pattern displayed isused by CAM or computer-assisted manufacture to produce a tool pathprogram for the fabrication of the dental mold. The tool path program isused to direct and control a machine tool. The machine is preferably ofmulti-axes. The program will direct a milling cutter or cutters in themilling of a tooth mold from a suitable substrate, for example, steel,nickel, aluminum, ceramic, plastic or any machinable material. Steel isthe preferred substrate. After the mold has been cut, the tool pathprogram is preferably used to direct and control the application of thefinish-polish to the mold. The finish-polish step improves the surfacefinish and results in a mold suitable for the manufacture of artificialteeth. A final hand-applied finish-polish step is optional.

Tooth molds for the manufacture of an artificial tooth requires a highdegree of definition to produce the labial striations or markings on atooth and multiple molds are needed to produce a blend of color capableof producing a natural appearance in the artificial tooth.

Imaging of enamel, shader, and back and second back mold parts is usefulin accordance with a preferred embodiment of the invention to make moldparts for production of central, lateral, and canine prosthetic teeth.Size proportioning for imaged enamel, shader back and second back fordifferent sets of teeth with a family of teeth provides proportionalconsistency of the teeth within the family. Specific points are selectedand distances there between are maintained proportionally constantwithin a family of teeth. Preferably thickness dimensions are measuredfrom the facial topography to keep consistency in the shape of the toothand in the enamel thickness.

In accordance with a preferred embodiment of the invention a shader andsecond back are imaged by first determining the overall labial length(L) of the tooth. The location of the shader and second back blendstarting locations PS and PB respectively are determined by multiplyingthe overall labial length (L) of the tooth by a different constant foreach tooth set of a tooth family. The back length (B) is then brokeninto portions each represented by a constant for each tooth set within atooth family. The shape and location of shader mold surface contours forcentral and lateral teeth and/or blend thicknesses are determined and/ordeveloped.

Images of an enamel mold part 200 and enamel layer 200A on display 202are shown in FIG. 2. Images of shader mold part 300 and shade layer 300Aare shown in FIG. 3. Images of second back mold part 330 and second backlayer 330A are shown in FIG. 4. Images of back mold part 350 and backlayer 350A are shown in FIG. 5. Display 202 is connected to computersystem 204. Preferably a tooth enamel mold part 208 is milled in a metalsubstrate by computer aided manufacture system 206. Mold parts 208, 308,332 and 352 are cut by computer aided manufacture system 206 withmultiple molding sites 209, 309, 334 and 354 as shown in FIGS. 2 through5. Preferably a prosthetic dental tooth, such as tooth 100, having ashade layer, such as shade layer 108, corresponding to shade layer image300 is formed in a molding site of a shader mold part, such as shadermold part 308. Each mold part is cut by computer aided manufacturesystem 206 with multiple molding sites therein, each of which is adaptedto form a layer of a tooth corresponding to a layer image. Preferablythe forming includes using a tool path program to direct machine cuttingand/or finishing-polishing the tooth mold part. Preferably polymerizableacrylate material is sequentially inserted between pairs of mold partsto sequentially form a prosthetic tooth having enamel, shade, secondback, and back layers. Thus, a preferred embodiment of the inventionprovides a prosthetic tooth including an enamel layer, a shade layer, asecond back layer and a back layer as shown in FIG. 1.

Shade layer 300 has two generally symmetrical curved groovescorresponding to groove images 310 and 312 between three curved ridgescorresponding to ridge images 314, 316 and 318, on the labial face ofthe shade layer at the incisal end of the tooth, as shown in FIG. 3. Thegrooves are deepest at the incisal end and extend substantially from theincisal edge to at least about 15 percent of the overall tooth length.Each groove 310 and 312 has a bottom that is substantially smooth. Thesides of grooves 310 and 312 intersect the plane of the top of ridges31, 316 and 318 at the ends of the grooves opposite to the incisal end320. Grooves 310 and 312 extend at least about 5 percent of the lengthsof shade layer 300. Preferably the tooth includes a tooth shade layerand a tooth enamel layer. Preferably the depth of each groove is fromabout 0.5 to 1.5 times the width of each groove. Preferably the crosssection of the shader mold upper surface adjacent to the incisal edgeforms a sine curve.

As shown in FIG. 5A molds for making readily articulable prostheticteeth, are made by displaying an image of at least a portion of at leastone upper tooth and at least one lower tooth. Each tooth is from thesame side of the same set of teeth. Data corresponding to the image ismodified whereby at least a portion of at least one is more nearlyparallel to at least a portion of the other tooth image. Teeth aremolded in molds made using the data. During articulation of these moldedprosthetic teeth the upper and the lower molded prosthetic tooth contactalong a larger proportion of each tooth surface than would be contactedwithout previously modifying while displaying the image of the tooth.

In accordance with a preferred embodiment of the invention is provided amethod of forming a shade pattern in a tooth including imaging an outersurface for a shader mold part from a labial surface image for a facemold part, cutting a shader mold part using a tool path program, andmolding a tooth having a shade pattern in a mold having the shader moldpart.

In accordance with a preferred embodiment of the invention is provided atooth family including a first tooth in a first family and a secondtooth in a second family. The first tooth has a first ratio of theoverall tooth length to the distance from the deepest point on thelabial surface of the neck of the tooth to the incisal edge of thetooth. The second tooth has a second ratio of the overall tooth lengthto the distance from the deepest point on the labial surface of the neckof the tooth to the incisal edge of the tooth. The first and secondratio being substantially equal. Such prosthetic teeth are preferablyprovided in a set which includes a first tooth having a first outersurface and a second tooth having a second outer surface.

In a preferred embodiment of the invention as shown in FIG. 6 isprovided a family of prosthetic teeth 400. Family of teeth 400 includessets of teeth 402, 404 and 406. Set of teeth 406 includes anterior teeth408 and posterior teeth 410. Set of teeth 404 includes anterior teeth412 and posterior teeth 414. Set of teeth 406 includes anterior teeth416 and posterior teeth 418. Anterior teeth 408 include upper teeth 420and lower teeth 422. Posterior teeth 410 include upper teeth 424 andlower teeth 426. Anterior teeth 412 include upper teeth 428 and lowerteeth 430. Posterior teeth 414 include upper teeth 432 and lower teeth434. Anterior teeth 416 include upper teeth 436 and lower teeth 438.Posterior teeth 418 include upper teeth 440 and lower teeth 442. Upperanterior central teeth 444 and 446, have shapes which are mirror imagesof each other. Upper anterior teeth 428 include central teeth 452 and454 which have shapes which are mirror images of each other. Lowercentral teeth 448 and 450 have shapes which are mirror images of eachother. Lower central teeth 456 and 458 have shapes which are mirrorimages of each other. Lower central teeth 464 and 466 have shapes whichare mirror images of each other.

Tooth 444 in set of teeth 402 has a first overall labial length, and afirst back length. Tooth 452 in set of teeth 404 has a second overalllabial length, and a second back length. The ratio of the first overalllabial length to the second overall labial length is substantially equalto the ratio of the first back length to the second back length. Tooth404 has a first shader length and tooth 452 has a second shader lengthand the ratio of the first shader length to the first overall labiallength is substantially equlength he ratio of the second shader lengthto the second overall labial length. Preferably this consistency ofthese ratio is present in corresponding molar, incisor and canine teethof different sets within family 400. Preferably the back length issubstantially equal to 94 percent of the overall labial length.Preferably the shader length is substantially equal to 68 percent of theoverall labial length.

Preferably the enamel thickness of prosthetic teeth of the inventionvaries less than 20 percent within a circular zone having a diameterequal to the thickness. More preferably the enamel thickness varies lessthan 15 percent within a circular zone having a diameter equal to twicethe thickness of the enamel. Most preferably the enamel thickness variesless than 25 percent within a circular zone having a diameter equal tothrice the thickness.

Preferably the enamel thickness at a selected point on the labial facebetween 20 percent and 75 percent of the overall labial length of thetooth is within 0.003 inch of the thickness at any other point within0.005 inch of the selected point. Preferably the outer surface of theenamel and the interface of the enamel with the shade layer havingsubstantially the same contours within a zone of constant enamelthickness.

Prosthetic teeth such as tooth 100 useful for making full and/or partialdentures, crowns, implant teeth and shade guide. FIG. 7 shows a shadeguide arm 500 supporting prosthetic tooth 502. Arm 500 has bends 504 and506. Tooth 502 is connected to arm 500 by connector 508. An implantcrown 601 has an enamel layer 602 having a zone of substantiallyconstant thickness and a shade layer 603 as shown in FIG. 8. Crown 601is supported by core 604. Core 604 is connected to post 606. Post 606 issupported by sleeve 608. Sleeve 608 is bonded to carbon implant 610.

In accordance with a preferred embodiment of the invention digitalinformation or data representative of a tooth enamel outer surface isprepared or retrieved from memory of a computer loaded with CAD/CAMsoftware program, for example a Sabre 5000 CAD/CAM System, availablefrom Gerber Systems Technology, Inc., South Windsor, Conn. The data isedited using the CAD/CAM system and two and/or three dimensionalmodel(s) displayed on a video display monitor. The operator then offseta copy of enamel outer surface and edit the copy to design and shaderouter surface. Once an acceptable surface pattern is generated. Softwareis used to generate a tool path program for the making of the dentalmold. The data in the form of the numerical coordinates of the tool pathprogram are collected on a memory disk and down loaded or transferred toa floppy disk.

In accordance with a preferred embodiment of the invention the floppydisk is down loaded into the hard disk drive of a milling, driving,boring and contouring machine for example a BostoMatic Model 312-1SVertical CNC Bed Type Precision Milling, Drilling, Boring and ContouringMachine, available from Boston Digital Corporation, Milford, Mass. Thetool path program is used to direct and control the machine in thefabrication of the tooth mold. The feed rate average is 6 inches perminute (range 4.5-10 inches per minute), at 30,000 rpm, for fourconsecutive passes with mills of decreasing size. A quarter inch endmill (Bassett) is followed by an eighth inch end mill (Bassett),followed by a sixteenth inch ball end mill (Bassett), followed by athirty-second inch ball end mill (TSC Carbide). The tool path accuracyis 0.0002 inch and the stepover range is 0.0005-0.001 inch. The machinehas four axis capability but only three axes were used in the making ofthe mold. The mold is cut into a block of 416 free machining stainlesssteel. The resultant mold is tested for surface finish qualities bysubjective visual evaluation with the trained eye at 7× magnificationcomparing stone impressions from the mold with the aluminum bronzemaster die. The machined mold contains approximately 95% of the surfacedetail and finish of the master die. The mold is a coupon that ismounted into a standard aluminum mold frame for proof molding.

Finish-polishing is accomplished with the finish tool path program forexample using a finish-polishing tool. The finish-polishing toolcomprises a hard wood polishing stick and is used with a diamond paste;the finish-polishing step is used to get as close as possible to thecomplete and acceptable surface detail and finish. A final handpolishing step may be carried out using a dental handpiece (power tool),brush (synthetic bristles), and jewelers' rouge.

For making the back mold part, the digitized information from the scanof the aluminum bronze master die is processed up to readiness to bedown loaded into the hard disk drive of the milling machine. For makingthe shader mold part, a soft Babbitt master shader die (not coated witha glarefree substance) is placed on a revolving support and processed inthe same manner as the aluminum bronze master die described above. Thedata is processed in the same manner as for the aluminum bronze masterdie information up to readiness to be down loaded into the hard diskdrive of the milling machine. The data is smoothed on the screen duringediting to assure the fit of the shader mold part into the face moldpart.

In accordance with a preferred embodiment of the invention is provided amethod of repeatedly molding high definition artificial dental teetheach having a molded enamel layer (coating). The method optionallyincludes scanning a model of a dental tooth. The method includes millingto make at least three mold parts. Each part is milled with a first millby executing a first pass along a first tool path to remove material toform multiple cavities in a first metal block to make a multiple cavitymold part adapted to form multiple dental prosthetic teeth. The millingis directed by a milling program which uses edited data. The edited datais obtained by editing reflection data using a design program. Thereflection data is representative of the surface of the tooth model. Theedited data is representative of the surface of the dental artificialteeth. The edited data is adapted by the milling program to direct themilling along the tool path. The mold parts are used to repeatedly moldhigh definition artificial dental teeth each having a molded enamellayer (coating). When scanning of a model is used each said cavity isthe negative of a portion of the model of a dental tooth to be molded inthe mold. The program is produced by the steps of imaging the surfacecontours of the dental model and producing data readings in response tothe imaging of the surface contours of the model.

In accordance with an embodiment of the invention is provided a methodof making artificial dental teeth each having a molded enamel layer(coating) and high definition labial striations. Optionally a dentaltooth model is provided scanned. Reflections from the tooth model arereceived, translated into electronic signals, which are then convertedinto reflection data. The reflection data is edited to add highdefinition labial striations using a design program to provide editeddata and fabricating a metal tooth mold part. The fabricating stepcomprising using the edited data to direct machine milling of said toothmold part. The milling comprising making a first pass with a first milland making a second pass with a second mill, the first mill having afirst mill end, the second mill having a second mill end, the secondmill end being smaller in size than the first mill end, High definitionartificial teeth are repeatedly molded using the mold part. Each toothhas a molded enamel layer (coating) and high definition labialstriations. The scanning may comprise directing a laser beam onto thedental tooth model. The optional scanning step may include rotating thedental tooth model during said subjecting and receiving steps. The toothmodel may be a three-dimensional wax or metal containing replica of atooth.

The model may have a glare-free coating. The processing step may includecreating an edited three-dimensional surface pattern of the tooth modelfrom the edited data, evaluating the surface pattern of the dental toothmodel, and creating a tool path program from the edited data. Theevaluating step may include visual analysis of the surface pattern ofthe dental tooth model and comparison to known geometric values for thetooth model. The fabricating step may include using said tool pathprogram to finish-polish the dental tooth mold part.

In accordance with a preferred embodiment of the invention is provided amethod of molding artificial dental teeth each having a molded coatingand labial striations. Optionally the method includes scanning athree-dimensional replica of a tooth having three-dimensional surfacelocations while rotating the replica. The reflections from said replicaare received and translated into electronic signals, which are digitizedinto reflection data. The reflection data is edited to add highdefinition labial striations in a computer using a CAD/CAM program. Atool path program is created using the edited data. The tooth mold isfabricated using the tool path program to direct machine milling of afirst, second and third metal artificial dental teeth mold parts. Themilling of the first metal mold part from a first metal part includesmaking a first pass with a first mill and making a second pass with asecond mill to mill the first metal part. The first mill has a firstmill end. The second mill has a second mill end. The second mill end issmaller in size than said first mill end.

The milling of the second metal mold part from a second metal partincluding making a first pass with the first mill and making a secondpass with the second mill to mill the second mold part.

The milling of the third metal mold part from a third metal partincludes making a first pass with the first mill and making a secondpass with the second mill to mill the third mold part.

The fabricating step may use the tool path program to direct machinefinishing-polishing the mold part. Preferably polishing of at least oneof the mold parts is directed by a finish tool path program. Preferablymilling a pattern of a layer of dental prosthetic tooth to make a moldis directed by a milling program which uses edited data. The edited datais preferably provided by editing reflection data using a designprogram. The reflection data is representative of the surface of a toothmodel. The edited data being representative of the surface of saidedited dental prosthetic tooth. The data is adapted by the millingprogram to direct the milling.

The polishing preferably includes finish-polishing using a finish toolpath and a finish-polish tool, such as a wood tool. The tool ispreferably used with a paste, such as diamond paste.

In accordance with a preferred embodiment of the invention is provided amethod of molding artificial dental teeth each having a molded enamellayer (coating) and labial striations.

The method includes milling multiple patterns of layers of artificialteeth in first and second portions of mold making material to make firstand second mold parts. The milling is directed by a milling programwhich uses edited data. The edited data is provided by editingreflection data using a design program. The reflection data isrepresentative of the surface of a tooth model. The edited data isrepresentative of the surface of the artificial tooth. The edited datais adapted by the milling program to direct the milling of said firstand second mold parts. The milling of the first mold part includesexecuting a first pass with a first mill and executing a second passwith a second mill. The first mill has a first mill end. The second millhas a second mill end. The second mill end is smaller in size than thefirst mill end. The milling of the second mold part includes executing afirst pass with a third mill and executing a second pass with a fourthmill. The third mill has a third mill end. The fourth mill has a fourthmill end. The third mill end is smaller in size than the fourth millend. By repeatedly molding polymerizable material in the mold highdefinition artificial dental teeth are formed each having a moldedpolymerizable material enamel layer (coating) and labial striations.

Preferably the mold making material is readily machinable andpolishable, such as steel, nickel, aluminum, ceramic or plastic.

Preferably the mold making material is steel, nickel, aluminum, ceramicor plastic. Preferably the milling includes making a second pass alongthe tool path with a second mill having a second mill end. The secondmill end is smaller in size than the first mill end. Preferably themilling includes a making third pass along the tool path with a thirdmill having a third mill end. The third mill end is smaller in size thanthe second mill end. Preferably the milling includes making a fourthpass with a fourth mill having a fourth mill end. The fourth mill end issmaller in size than the third mill end. Preferably the mold part is aface mold part, a shader mold part, a second back mold part or a backmold part. Preferably a point of contact with a second part is providedusing a surface pattern of the mold. Preferably the milling with thefirst mill is by executing a first pass along a second tool path toremove material to form multiple cavities in a second block to make amultiple cavity second mold part. Preferably the milling with a secondmill is by making a second pass along the second tool path to removematerial from the second block.

It will be apparent to those skilled in the art that variousmodifications and changes may be made in the practice and use of thepresent invention without departing from the scope thereof as set forthin the following claims.

What is claimed is:
 1. A prosthetic incisor tooth comprising a toothbody, said tooth body being formed from polymerizable material andhaving an incisal end and a labial face, said incisal end being adjacentto and extending from an incisal edge, said labial face having anoverall labial length extending from the incisal edge over the length ofsaid labial face, said labial face having an average width across saidlabial face, said tooth body having two generally symmetrical curvedgrooves between three curved ridges on the labial face of the body, saidgrooves being deepest toward the incisal end of said tooth, said groovesextending from the incisal edge for at least about 5 percent of theoverall labial length, each said groove having an average width equal toat least 5 percent of the average width of said labial face of saidtooth.
 2. The tooth of claim 1 wherein each said groove has a bottom,and the said groove bottom is substantially smooth and intersects theplane of the top of the ridges at the ends of said grooves opposite tosaid incisal end.
 3. The tooth of claim 1 wherein each said grooveextends at least about 20 percent of the overall labial length and atleast 10 percent of the average width of said tooth.
 4. The tooth ofclaim 1 further comprising a tooth shade layer and a tooth enamel layer.5. The tooth of claim 1 further comprising a tooth shade layer and anenamel layer.
 6. The tooth of claim 1 wherein said tooth has a shadelayer and said grooves extend from the incisal edge for at least 15percent of the overall labial length.
 7. A method of forming a shadepattern in an incisor tooth, comprising:imaging an outer surface imageof a shader mold part from a labial surface image for a face mold part,milling a shader mold part mold part using a tool path program, least aportion of an outer surface of said shader mold part, corresponding tosaid outer surface image, and molding a prosthetic incisor tooth havinga shade pattern in a mold having said shader mold part, said prostheticincisor tooth comprising a tooth body, said tooth body being formed frompolymerizable material and having an incisal end and a labial face, saidincisal end being adjacent to and extending from an incisal edge, saidlabial face having an overall labial length extending from the incisaledge over the length of said labial face, said labial face having anaverage width across said labial face, said tooth body having 2generally symmetrical curved grooves between 3 curved ridges on thelabial face of the body at the incisal end of said body, said groovesbeing deepest toward the incisal end of said tooth and extending fromthe incisal edge for at least about 5 percent of the overall labiallength, each said groove having an average width equal to at least 5percent of the average width of said labial face of said tooth.
 8. Themethod of claim 7 wherein said tooth shader mold part is milled in ametal substrate.
 9. The method of claim 7 wherein said forming comprisesusing a tool path program to direct machine finishing-polishing saidtooth mold part.
 10. A method of making readily articulable prostheticteeth, comprisingdisplaying an image of at least a portion of at leastone upper tooth and at least one lower tooth, each said tooth being fromthe same side of the same set of teeth, modifying initial datacorresponding to said image to form modified data, molding readilyarticulable prosthetic teeth in molds made using said modified data,whereby, during articulation said readily articulable prosthetic teethcontact along a larger proportion of tooth surface than prosthetic teethmade in molds using said initial data.
 11. The method of claim 10wherein each of said upper tooth and said lower tooth is a molar tooth.12. The method of claim 11 wherein said enamel thickness varies lessthan 15 percent within a zone having a radius equal to twice saidthickness.
 13. The method of claim 10 wherein said prosthetic tooth,comprises an enamel layer and a tooth body, said enamel layer having anouter surface and a zone of thickness which varies less than 20 percentwhen measured along a line extending normal to said outer surface. 14.The method of claim 13 wherein said enamel thickness varies less than 15percent within a zone having a radius equal to twice said thickness. 15.The method of claim 10 wherein said prosthetic tooth, comprises anenamel layer and a tooth body, said enamel layer having a zone of enamelhaving substantially constant thickness when measured along a lineextending normal to said outer surface, said enamel thickness variesless than 20 percent within said zone, and said zone has a radius whichis at least equal to said thickness.
 16. The method of claim 10 whereinsaid prosthetic tooth, comprises an enamel layer and a tooth body, saidenamel layer having a zone of substantially constant enamel thickness,said enamel layer having an outer surface and an interface with a shadelayer, and said outer surface and said interface having contours ofsubstantially the same size and shape within said zone.
 17. The methodof claim 16 wherein said enamel thickness varies less than 15 percentwithin a zone having a radius equal to twice said thickness.
 18. Amethod of repeatedly molding high definition artificial dental teetheach having a molded enamel layer with at least one zone having asubstantially constant thickness, comprising:displaying at least aportion of at least one dental tooth layer and/or mold for said layer,and milling a first multiple cavity mold part with a first mill byexecuting a first pass along a first tool path to remove material toform multiple cavities in a first metal block adapted to be used with asecond mold part to form a layer of multiple dental prosthetic teeth,each said prosthetic tooth, comprising an enamel layer and a tooth body,said enamel layer having an outer surface and a zone of thickness whichvaries less than 20 percent when measured along a line extending normalto said outer surface, said milling being directed by a milling program.19. The method of claim 18 further comprises repeatedly molding in saidmold high definition artificial dental teeth each having a molded enamellayer.